Mold foe pneumatic-tire tubes



l F. A. SCHWARTZ. Mom FOR PNEUMATlc IRE URIG|NAL F LED AUG,

Jan. 2, 1923.

.0a. 39N? 1 9d.

R'eiasued Jan, 2.,

`Fiumi) A., SCHWARTZ, orfcosnocromgoino; f

uw MOLD ron rNEUMATic-rrnn 'ruinasr 'original No. 1,383,382, ydated 'Augustaa1921,seriai No.'44'3,91'7,` niedrebmari 1o, 1921-.,

for reissue .med lJuly@ 17,

To Z-Zlwhloiii it may 'concerney y, i p f Be it -known ythat I, FRED A. SCHWARTZ,

State of Chio, have invented certain new and useful Improvements in Molds for Pneumatic-Tire Tubes; yand I hereby declarel the Afollowing to be a full, clear, yand eXact description of the, invention, s'uch as will 'enable others skilled in the art rto which it pertainstomakeand use the same.

The invention relates to the construction and vulcanization of casingsthat are used in combination With vpneumatic tubes, 'the 1 said combination being usually referred rto as the .pneumatic tire. y

The obje@ of the inventan .is to'povide y means to correct -c'ertainfaultyy conditions that obtain with Aordinary methods oiicon-` structingand vulcanizing casings..

. In the vprocess of vulcanizing casings it has been demonstrated that lbetter -results rvare obtainable when `the fabric structure of the casing subjected to pressure that is applied in the direction of the radii of they `'casi simultaneouslywith. pressure that impu ses the companion casing forming mold parts'. .n s

To this end various means are beingr employed, as for example, the casing to vulcanizedis removed from the rigid vcore upon which itis constructed vand vthere is substituted an elastic core 'by which means -t'he casingis lduring` lthe process of vulcanilnation subjected to an expanding pressure "that is admitted to. Within the elastic core. With vmy iriventionin use, similar results are` obtained, and Without thev expense of renewing at frequent intervals the 'elastic' cores, and with a considerable saving in.

time 'and labor consumed l in bolting or lclamping 'companion casing forming mold parts `against lthe internal pressure.

swill be made plainly evident in this specification, by lreason of thejnovel AconH formation y of Vthe 'surface areaV ofthe improved core, and. grooves of the companion casing forming moldA parts', 4the `fabric orv 'co'rd structurepfthe 'casing during the process of vulcaniza'tion,l is, by the use of` my inventionsubjeotedto stress that is applied 't'O. the 4fabric vor. cord'stue'tlii'e. -the direc- 'a citizen of the United States, residing at* Coshocton, in the county of Coshocton and i 1922.- seria1iw0.575,c41. l

Application i tion of the lplane of the ofthe 'i casing simultaneously to Vthe compressing aCtlO'n 'of the casing formingmold parts.

vIn Ythe "accompanying drawings which form a part of -this specification, Figure 1 is a cross section ofthe vulcanized casingin 'association vvith a cross section of the im@` 'proved equipmentr 5g' the core" and companioii casing forming mold .parts Which-comprise Ythe improved equipment being in their rela- 'tive operating-position. asfassumed during the inal stageof the 'process of vulcaniza- -1 f l 'e5 tion ofthe casing.

Fig. 2 is 'a ragmentary'cross section of the Avirilcanized casing, illustrating. by 'broken lines the conformation asv assumed'b'y the side Walls of the casing lwhen yin use.'- v

Fig.` 3 is ya viewsi-milar Ito Fig. 2, illus- Vtr'it'ing'the methody of building or mounting y `the ufnvulcanized-casing upon the core.

` The improved vequipment may beem- I ployed inthe constructiona'nd vuloanization lof casings of the clenehei-,or straight side type, and the. core 'forming-a partei the improved equipment may be or co1*- lapsible, and While lthe equi'pineiitl-ris-moie Aparticularly vintended for' use lthe v,Covn- ,i

struction and vulcanization ofcasings of the .cordjply constructioindby .the use of my improved equipment Casin s of superior quality may be produced int ply construction.

The?. fun rtion of .the improved-equipment ewwove'n' fabric is positivelyreliable, and results fromvthe y novel :method of building orhmountinglthe casingupon the core, andl by jthef conformation given Athe side Wallsof thecasingdur-fj ing the'prooess of vulcaniza'tionup Thernethod of building, Vorconstructing the casing 'upon the improved core is ysub- `stantially the same as when. employing the ordinary equipment; 3 that lis, `the fbody, fof ,the casing consists of-sev'eral-layers, or "plies of rubberized fabric `o1' cord, and upbn which structure 'the outerxlelemeiits of the casing, as the-'treadbeads, andjsidewalls of rubber lcompounds, are. secured-by .vulfr caniza'tion.r

` Referring. to F ir,faiid to core which may be. constvuotedby enyiireferred method, .as forvexample itmaiy solid,

'or (hollow, or it-maybe .constructed cate'dby vvthenumerals 3, willl also be .noted th'atf'these grooves are positioned at suliistantially the central circumferential line between the :inner-,and l enter; peripheries .ofthe core, and that the conjunction of the concave andconvex areas 'are aifectedby regular, but shorter curved areas', the importance ofwvhich will belater apparent,

,'When buildingxthecasing upon the improved core the surface area of the core` between the vinner edges'l, 4, "of the grooves and ytheinwardly directed flange 5, isvgiven azcoveiingfofrubberfcenientg the rstplyy' N t l l i the raw tire or casinghasbeen built"A "6, 'ofl fabric or cord is placedv upon the Icore ands`titched,"r that is th e-ply is causedto c0nedgesare securedjtofthe core by the adhesive qualitiesro'f the rubber ,cement` EAs Will'be vobserved by" referring to the numerals 7, 7,

ig.`3,"; the fabric ory cord Astructure" of the casing is not caused to .conform toi" the surfacefarea of thegrooves; the'result isthat y when the casing is finally completed bythe casing `b'uilder,` there is- `space, between the ysurface area ofrlthe grooves. 3, 3,' andthe y'inner-surface of the unvulcanizedlcasing.

'lghe operation" vofthe improved equipment "when the casingy is to be vulcanized isfas folloivs''Referringtothe casing forming mold parts, and to the Aannular casing forming Y gr0oves'8,"8, Fig. l, it will be observed that 35, t v g are oset from theinner or mold sides of the circuinferentially' directed ribs 9, 9, that Avvthe "annular"` casing forming grooves 8, S,

` upon `thesurface of the core.

aline'vith, and With the casing formingiinold partsin closedpposition engage the grooves i 3, 3,' which are circumferentially directed (It is understood-.that proper clearancevis provided vfor the casing. between the lribsv and grooves 'When the'mold parts'are in closed position.)

By the means just described, ,the side Y"Walls ofthe casing are vduring theprocess of vulcanization caused to conform to the suru*face*Tarea of the annular grooves inthefcore,

"andthe annulargribs off-set from the. curved lsurface?area of the casing forming grooves. Thus the surplus fabricor cord stock, that l'results from theclosing action vof the vmold 1 l is takenv up `bv *the surface area' of th partsv compressing 'the several fabric plies e Vcore from thel :core in the fusual" manner. The

vulcanized, but :notinfhated` casingy is 'ofthe sameiconformation as the surface`V areaof the casing'forminggrooves in the ncompany ififmold arts' in whichV the' casing has been vulcaaze but by reason of the pressure` exertedupon theside WallsA ofthefcalsing by the' ,infine,cilv firmer' ai; tube, theI easing when` ture lof the Casin ings.

I nished )surfaces et the core,v I i It Willbe seen alS'othat Ifhave provided `stretch every part of fabric and that this 'equal transverse stretchthe tire insures n a uni- Vcompressing pressure in the ,directionof lthe plane of the sidewalls of the casing,vthe .vresult of which will eiiect a thickeningo the y rubber compound covering the` `fabric strucg. Thus the flexing, and refiexing action ofthe casing when in use will bemuch betterwithstoodby the rubber compound projecting into the fabric'structuren'of the casing-atthis inostvulnerable point;

over anoncompressiblecore 2, as shown in Fig. 3'ofthedrawingsfand in` which vit will be noted that the coreis 'of regular 'contour approximating the shape of vthe tire with the i exception of a mnorlportion lof 'thecontour I, 1n-Which `portions have been 'cut away or each side of the tireor casing Will be [forced .into the cavities formed by'` the channels 3, since the circumferentially.' directed ribs aline With "the annular casing forming yin service will assume the regular curvedV f confo'rmation as lndlcated by the broken during the vulcanizlng process, a ,section` of' grooves 3,'and conform inl contour'tofthe contour ofthe latter. As the lbead rings are securely held in place by lthe'bottoin contourof the vmold it Will be obvious that the distortion'of the sides ofthe tirecasing at` -fpoints" above such beads Will produce a transverse stretching of all the layers `of rfi'abric or cord and `a positive stretching of yevery section of eachvlayer as Will bef obviousi/upon reference to'Fig. l of the `dravv- V 2 of the drawings dotted lines therecasing is substanshape when completed and` and vulcanized, asishown in Fig. 2, as when" built up on the improved core beforevulcanizing as shown in Fig. 3, with the exceptionfthat the finishedr casing may be `lUpon reference to Fig. it will be noted from the in: that the built up tire tially the same A somewhat larger due to the Istretching action',

caused by temporarily b y distorting aportion of the tire ateach sidey through `the instru- [mentality of the ,circumferentially directed ribs 9,'` 9, registering with and cooperating Wlth the grooves or channels stretchingrneans'in the coacting" core and casing forming mold parts that ywill equally `each layer of cord or ingof every.partot:- form stretchingofeach-layer and a proper 3L onv the side proportioning of every part of the tire in ac; cordance With the mold and core design thus positively eliminating all. possibility `of 'buckling,.rim cutting or other similar tireL irregularities.v It will be seen furthervthat in vulcanizing the'tire by applying pressure i l.directly by means of molds against a solid 4 tempted to set `forth all the forms in whichl central core I have made it possible to cure and tension tires under a much greater pres-` sure than by the use of air bags, or `the like,

, and with the result that there is less separation of plies and a subsequent prolonging of the life of a tire. Having thus described one of the embodiments offmy invention, Without having atit may be made, or all the modes of its use,

.what 1I claim and desire to securey by- Letters lao Patent, isl l. The method of forming tires, which consists in forming the tire casing'about a core having side grooves, and pressing a portion of the tire into the said grooves.

2. The lmethod of forming tires which consists in initially building up a vtire of. substantially the shape desired, and then distorting said tire circumferentially kand vul# canizing.

3. A tire former comprising a tire core,v

having circumferential channels vformed on its sides, and a mold having corresponding circumferential ribs designed to press porl tions of said tire into said channels.

4. A mold for-pneumatic tires, comprising an' annular core provided With annular grooves in its sides, and companion tire formin core. K y

5. The `method of forming tires which consists in building up a tire of substantially mold parts having annular ribs registermg wlth said annular grooves 1n said Acore having oppositely arranged circumfer entially extending grooves, and a pair of complementary annular casing forming` mold parts having interior. annular ribs arranged in registration with said circumferentially extending grooves.

`8,. A casing mold comprising a pair ofy complementary annularsections each having an, annular rib .offset from' its annular concave molding surface, andan annularA core element having a molding surface normally extending between the vvsaid complementary annular sections,'the said annular'core element having grooves opposite said annular ribs. t

9. The method of forming tires Whichvconsists in building up a tire about a core hav'- ing its major portion of substantially the shape of the interior of the tire to be formed and having minor vportions in its sides form,- ing annular recesses, and distorting saidtire through the medium of annular complementary mold sections having interiorl annular ribs arranged in registry with said annular recesses and adapted to press corresponding annular sections into said recesses.

In testimony whereof I have aliixed my signature. 4

FRED A. SCHWARTZ. 

